Alcoholism is a common heterogenous disease. Heritability has been established in both men and women, but as for other psychiatric diseases, it has proved difficult to map genes directly for reasons such as genetic heterogeneity, phenocopies, penetrance and expressivity, and polygenic effects. We have identified a trait- specific marker for alcoholism vulnerability, the low voltage alpha (LVA) EEG, a normal variant of the resting EEG in which the alpha rhythm is virtually absent. This phenotype is strongly heritable, traitlike, present in 4-11% of the population and accurately determined. We now have a complete data set, including EEG and ERP phenotypes, blind- rated DSM-III-R diagnoses, psychometric tests and DNA on 247 individuals. We have recently replicated the association of LVA with a subtype of alcoholism with anxiety in a comparable sample of 149 unrelated individuals (Enoch et al 1999). LVA was found in 23% of alcoholics, 25% of subjects with an anxiety disorder and 56% of alcoholics with an anxiety disorder compared to 8% of the individuals without alcoholism or an anxiety disorder. In order to obtain sufficient power to map genes for alcoholism, the focus of this study has shifted to a Plains American Indian tribe which has a high prevalence of alcoholism. During the course of this year we performed EEGs and ERPs on 374 tribal members from large pedigrees. We have almost completed the data set of psychiatric diagnoses and DNA from these individuals.We will soon be in a position to start analyses for mapping genes for alcoholism.Formerly titled Genetic studies of the electroencephalogram and event-related potentials. - health & behavior, neurosciences, drinking patterns & causes, electrophysiology/EEG, molecular genetics - Human Subjects: Interview, Questionaires, or Surveys Only